Telecommunication link interfaces couple communicating equipment, referred to as customer premises equipment (CPE), to a communications network comprising one or more telecommunication links that transport the communications of the CPEs between the CPEs. Various link interface designs for various networks are well known in the art. An illustrative example is the synchronous packet data interface disclosed in the U.S. Pat. No. 4,577,314.
Until recently, digital communication networks have operated at relatively low transmission rates, up to about 10 Mbps maximum, and conventional link interface designs have served these networks well. However, as network transmission rates are rising, and proposals are made for digital networks operating at hundreds of Mbps or even Gbps, conventional link interface designs reveal a crucial flaw: they are generally unable to operate fast enough to handle these high transmission rates. The above statement tends to be especially true in the case of interfaces to packetized transmission networks, where the interfaces must perform many complex packet-creation and packet-disassembly functions. An example of such an interface is the one disclosed in the patent referred to above: in known implementations, its rate of operation is less than 1 Mbps.
The problem is further exacerbated for multiplexed (i.e., interleaved) communications: not only must the link interface handle the link's transmission rate, but it must additionally perform multiplexing and demultiplexing functions with respect to communications being transmitted and/or received on the link. An illustrative example of a link interface arrangement that tries to deal with packetized asynchronous time-division multiplexed (interleaved) communications is disclosed in U.S. Pat. No. 4,885,744. This arrangement deals with translating existing slow-speed protocols to higher-speed networks, but does not address providing a high-speed interface directly to take advantage of the higher-speed networks. I believe that existing interface arrangements that use the slow-speed protocols will not satisfactorily scale up in speed. New arrangements will therefore be required to fully take advantage of high-speed networks.